Heat exchanger assembly

ABSTRACT

A heat exchanger assembly has a first manifold, a second manifold in spaced and substantially parallel relationship with the first manifold and a plurality of flow tubes fluidly connecting the manifolds for passing refrigerant between the manifolds. The first manifold includes a header and tank which are joined by their longitudinal edges to form a cavity. The tank is extruded and has an outer wall and an inner partition wall with a plurality of apertures which define a distribution chamber within the cavity. The distribution chamber is fluidly connected to the cavity. A method of manufacturing a manifold generally includes the steps of extruding the tank, cutting the tank to a predetermined length, forming a plurality of apertures in the inner partition wall, forming a plurality of openings in the header, joining the tank and the header, and joining the end cap to the tank and header.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat exchanger assembly and method of manufacturing a manifold.

2. Description of the Prior Art

Heat exchanger assemblies are widely used in a variety of applications, and can be either single mode or dual mode, depending on whether functioning solely as either a condenser or an evaporator, or if functioning as both. The heat exchanger assemblies generally include a pair of manifolds fluidly connected by a plurality of flow tubes. Heat conducting structures, such as fins, are generally disposed between the flow tubes to add surface area to the heat exchanger assembly for further aiding in heat transfer to or from ambient air passing over the flow tubes. Refrigerant enters the heat exchanger assembly through one or more ports which are connected to one or both manifolds. Refrigerant passes through the heat exchanger assembly and is exited through one or more ports connected to one or both of the manifolds.

One of the primary goals is to maximize heat exchange efficiency by managing the velocity and distribution of the refrigerant, as well as the temperature and pressure differences within the manifolds and the flow tubes. A difficulty arises because the flow characteristics of the refrigerant vary depending on the phase, that is, whether the refrigerant is a gas, liquid, or combination. When there is poor refrigerant distribution and circulation, some sections of the heat exchanger assembly can be flooded with refrigerant and some can be starved, resulting in unequal heat transfer between portions of the heat exchanger and can cause icing or frosting of portions of the heat exchanger, further diminishing performance.

The largest problems exist when the heat exchanger assembly is operating as an evaporator in order to absorb heat. The refrigerant enters the heat exchanger assembly in two-phases, comprising liquid and gas. As the two-phase refrigerant circulates through the heat exchanger assembly, the refrigerant absorbs heat from the ambient air passing over the flow tubes and other heat conducting structures, causing the liquid to further evaporate and the gas phase to further expand. Momentum effects due to large mass differences between the liquid and gas phases causes separation of the two-phase refrigerant. Separation of the phases adds to the already present distribution problem within the passes, which further decreases overall heat exchange performance of the evaporator.

Manufacturing costs, particularly assembly costs, can be high because of the number of components, and the precision with which they must be installed to ensure proper alignment. Conversely, producing single integrated manifolds can present a lack of flexibility in selecting materials and limit manufacturing access to the interior of the manifold.

A single piece extruded tank is disclosed in PCT Application WO 93/04334 to Creamer, et al. While this single piece extruded tank reduces the number of components, it does not include a structure for facilitating refrigerant distribution.

A distribution tube is disclosed within a manifold of a heat exchanger assembly, specifically, a refrigerating coil, in U.S. Pat. No. 1,684,083 to Bloom. The distribution tube forms a distribution chamber and includes a plurality of apertures for distributing refrigerant entering the manifold. The distribution tube is a separate component joined to the manifold by welding, and thus the problems related to assembly costs and the difficulty of positive placement of the distribution tube are not addressed. Further, the shape and configuration of the resulting distribution chamber is limited.

Accordingly, there exists an opportunity to manufacture a tank for a manifold of a heat exchanger assembly that has an integral distribution tube that allows for robust construction and positive placement of the distribution tube. Flexibility in options for creation of apertures in the distribution tube would also be beneficial.

SUMMARY OF THE INVENTION AND ADVANTAGES

The subject invention provides for a heat exchanger assembly having a first manifold with a tank and a header adjacent the tank defining a hollow cavity. A second manifold defines a hollow cavity and is in spaced and substantially parallel relationship with the first manifold. A plurality of flow tubes extend between and fluidly connect the cavities of the manifolds for passing the refrigerant between the manifolds. The tank has an outer wall defining a channel and an inner partition wall disposed within the channel adjacent the outer wall. The inner partition wall has a section integrally formed with a portion of the outer wall to define a distribution chamber disposed within the channel. The inner partition wall has a plurality of apertures fluidly connecting the distribution chamber with the cavity.

The subject invention also provides a method of manufacturing a manifold having a tank with an outer wall defining a channel and an inner partition wall with a plurality of apertures, a header having a plurality of openings, and at least one end cap. The method includes the following steps: extruding the tank having the outer wall and the inner partition wall with the inner partition wall integrally connected to the outer wall to form a distribution chamber; cutting the tank to a predetermined length; forming a plurality of apertures in the inner partition wall; forming a plurality of openings in the header; joining the tank and the header; and joining the end cap to at least one end of the tank and the header.

An extruded tank which includes an integrated distribution chamber reduces the assembly complexity. Problems associated with mechanical assembly, location and joining of separate distribution tubes, in particular, for longer manifolds, are completely avoided. At the same time, because the interior of the tank is easily accessible, tremendous flexibility is afforded in the creation of the plurality of apertures. Further, by having a separate tank and header, the header may be cost-effectively produced including a braze cladding which facilitates the joining of the header and tank as well as the header and the flow tubes.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein.

FIG. 1 is a perspective view of a heat exchanger assembly;

FIG. 2 is a perspective view of the first manifold of the heat exchanger assembly, illustrating a header, a tank and an inner partition wall;

FIG. 3 is a cross-sectional top view of one embodiment of the manifold;

FIG. 4 is a cross-sectional top view of another embodiment of the manifold;

FIG. 5 is a cross-sectional top view of another embodiment of the manifold;

FIG. 6 is a cross-sectional top view of another embodiment of the manifold;

FIG. 7 is a cross-sectional top view of another embodiment of the manifold;

FIG. 8 is a cross-sectional top view of another embodiment of the manifold;

FIG. 9 is a cross-sectional top view of another embodiment of the manifold;

FIG. 10 is a cross-sectional top view of another embodiment of the manifold;

FIG. 11 is a cross-sectional top view of another embodiment of the manifold;

FIG. 12 is a cross-sectional side view of the manifold including separators.

FIG. 13 is a fragmented side view of the manifold illustrating one embodiment of a port connected to the manifold;

FIG. 14 is a fragmented side view of the manifold illustrating another embodiment of a port connected to the manifold;

FIG. 15 is a fragmented side view of the manifold illustrating another embodiment of a port connected to the manifold;

FIG. 16 is a fragmented side view of the manifold illustrating another embodiment of a port connected to the manifold; and

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a heat exchanger assembly is generally shown at 20 in FIG. 1. The heat exchanger assembly 20 includes a first manifold 22, a second manifold 24, and a plurality of flow tubes 26 fluidly connecting the manifolds 22, 24. A plurality of heat conducting structures are disposed between the plurality of flow tubes 26, which are illustrated as fins 28. As is known to those skilled in the art, the first manifold 22 may be commonly referred to as an inlet manifold, therefore performing an inlet function, and the second manifold 24 may be commonly referred to as an outlet manifold, therefore performing an outlet function, however, the opposite could be true. Reference to the first and second manifolds 22, 24 is interchangeable in the description of the subject invention.

The first manifold 22 includes a tank 30 having a length, a first end 32 and a second end 34, and a header 36 adjacent the tank 30. The header 36 has a length substantially defined by the tank 30 and the tank 30 and the header 36 are joined to define a hollow cavity 38. An end cap 40 is shown being attached to each end 32, 34 of the first end 32 of the tank 30 and the header 36. The end cap 40 can include a cladding material for joining to the tank 30 and header 36 of the first manifold 22 using a variety of methods, such as but not limited to, brazing or welding.

A second manifold 24 defines a hollow cavity 42. The second manifold 24 has a length with a first end 44 and a second end 46 and is in spaced and substantially parallel relationship with the first manifold 22. It can be readily appreciated that though the second manifold 24 is shown as having the same general appearance as that of the first manifold 22, the second manifold 24 can be constructed differently than the first manifold 22, for example, but not limited to, the second manifold 24 can comprise a single extruded component. The end cap 40 is shown being attached to each end 44, 46 of the second manifold 24. The end cap 40 can include a cladding material, for joining the end cap 40 to the second manifold 24 using a variety of methods, such as but not limited to, brazing or welding. Though the heat exchanger assembly 20 is shown throughout the drawings with the manifolds 22, 24 being vertically oriented, it can be readily appreciated that the heat exchanger assembly 20 can be oriented in a variety ways to accommodate engineering requirements of a specific application, for instance, horizontal.

At least one port may be in the first manifold 22 and fluidly connected to at least one of the distribution chamber 66 and the cavity 38. The port may be an orifice or a tube, as is known in the art. The port may be an inlet, an outlet, or a combination of both. Referring to FIG. 1, one of the ports is an inlet port 72 and is fluidly connected to the first manifold 22 for introducing refrigerant into the heat exchanger and another of the ports is an outlet port 74 and is fluidly connected to the second manifold 24 for exiting refrigerant from the heat exchanger assembly 20.

Referring to FIG. 2, the tank 30 has an outer wall 56 defining a channel 58 and an inner partition wall 60 disposed within the channel 58 adjacent to the outer wall 56. The tank 30 may be manufactured in a single piece, such as by extrusion. The outer wall 56 includes a pair of opposed longitudinal edges 50 each including a flange 62 integral to and extending outward from the longitudinal edges 50 forming a seat 52.

Referring to FIGS. 2-3, the header 36 includes a pair of longitudinal edges 48 with a plurality of openings 54 sized for accepting the plurality of flow tubes 26. The header 36 has a generally arc-like cross-section. The openings 54 are typically elongated slots. It can be appreciated that the plurality of openings 54 can comprise different shapes including, but not being limited to, circles and rectangles. The plurality of openings 54 can be produced by any means, including but not limited to, drilling, lancing or punching. It can be readily appreciated that where the plurality of openings 54 are produced by lancing, it is possible to produce a dimpling effect adjacent the plurality of openings 54, which can facilitate the positioning and joining of the plurality of flow tubes 26 to the header 36. The header 36 can be produced by a variety of processes, including but limited to, stamping. Further, the header 36 can comprise a variety of materials, including but not limited to, an alloy of aluminum.

The plurality of flow tubes 26 are mounted to the header 36 and are disposed within the cavity 38 of the first manifold 22 fluidly connecting the cavity 42 of the second manifold 24 with the cavity 38 of the first manifold 22. In addition, the header 36 can include cladding material, such as but limited to, an alloy of silicon and aluminum. The cladding permits simple brazing of the plurality of flow tubes 26 to the header 36. The longitudinal edges 48 of the header 36 are inserted into the flanges 62 of the tank 30 where the longitudinal edges 48 of the header 36 are positioned adjacent the seats 52 and joined to the tank 30 by a process such as brazing.

Referring to FIG. 2-3, the inner partition wall 60 has a section 64 integrally formed with a portion of the outer wall 56 to define a distribution chamber 66 disposed within the channel 58. The distribution chamber 66 has a length generally defined by the length of the tank 30 and is substantially parallel to the tank 30. Referring to FIG. 3, the inner partition wall 60 has a generally C-shaped cross-section. The distribution chamber 66 is disposed within the cavity 38 directly opposite the plurality of openings 54 where the plurality of flow tubes 26 are inserted into the first manifold 22 body. The plurality of apertures 68 are disposed within the inner partition wall 60 and generally run along the length of the distribution chamber 66. It can be readily appreciated that because the inner partition wall 60 is easily accessible prior to joining the tank 30 and the header 36, a number of configurations are possible. The plurality of apertures 68 can comprise a variety of shapes and sizes, as dictated by engineering requirements for a specific application, including but not being limited to, circles and polygons.

Referring to FIG. 4, a second thickness T₂ of the outer wall 56 of the tank 30 and a first thickness T₁ of the inner partition wall 60 of the tank 30 can be the same or can be different from one another, and may be primarily dictated by burst pressure requirements. In addition, the second thickness T₂ of the outer wall 56 can be uniform or may vary. Similarly, the first thickness T₁ of the inner partition wall 60 can be uniform or may vary. A reduced first thickness T₁ may be possible because of the lower operating pressure between the cavity 38 and the distribution chamber 66, and can save space, weight, and cost. It may be advantageous to have the second thickness T₂ of the header 34 where the plurality of flow tubes 26 are joined be thinner than other portions of the tank 28, as also shown in FIG. 4. Though the cross-section of the outer wall 56 is generally illustrated as being circular, it can be readily appreciated that the outer wall 56 can be a variety of shapes. Referring to FIGS. 5-7, the cross-section of the outer wall 56 can include a protrusion, can be generally rectangular, or include additional structural support elements. Similarly, though the header 34 is generally illustrated as having an arc-like cross-section, it can be appreciated that the header 36 can have a cross-section that is more generally linear.

Referring to FIG. 6, in yet another embodiment, the flange 62 is shown having an L-shaped cross-section, forming a notched seat 52. It can be readily appreciated that the dimensions of the flange 62 can vary depending on the requirements of the application.

Though the preferred embodiment describes the inner partition wall 60 having a C-shaped cross-section, it can be readily appreciated that other configurations are possible. Referring to FIGS. 7-8, the inner partition wall 60 can have an arc-like or linear cross-section, depending on the requirements of the application. Alternatively, the formation of the plurality of apertures 68 can be facilitated by forming a ledge 70 along the length of the inner partition wall 60, as illustrated in FIGS. 9-10. It can further be appreciated that the distribution chamber 66 can be offset from the plurality of flow tubes 26 as illustrated in FIG. 11. This flexibility in the positioning of the distribution chamber 66 makes it possible to accommodate variations in plumbing, flow and refrigerant distribution requirements.

Referring to FIG. 12, a separator 76 can be inserted within the cavity 38 and/or distribution chamber 66 further dividing the cavity 38 and distribution chamber 66.

Referring to FIGS. 13-16, alternative port 72, 74 placements are illustrated. At least one port 72, 74 may be adjacent at least one of the outer wall 56 and the end cap 40 and fluidly connected to at least one of the distribution chamber 66 and the cavity 38, 42. The inlet port 72 may be fluidly connected to the distribution chamber 66, through the end cap 40 or the outer wall 56 of the tank 30. Similarly, both the inlet port 72 and the outlet port 74 may be fluidly connected to the cavity 38 of the first manifold 22 through the outer wall 56 of the tank 30 or through the end cap 40. It can be appreciated that the ports 72, 74 may be fluidly connected to the cavity through the distribution chamber. It can be appreciated that the ports 72, 74 can include a coupler 78. The coupler 78 may be useful for connecting external plumbing to the heat exchanger assembly 20 and may also be useful for manufacturing purposes. It can further be appreciated that the ports 72, 74 can be fluidly connected to the second manifold 24 as described for the first manifold 22, depending on the requirements of a specific application. It can further be appreciated that more than one inlet port 72 can be used to introduce refrigerant into the heat exchanger assembly 20 and more than one outlet port 74 can be used to exit refrigerant from the heat exchanger assembly 20.

The present invention also provides a method of manufacturing a tank 30 having an outer wall 56 defining a channel 58, and an inner partition wall 60 with a plurality of apertures 68. The method includes the step of extruding the tank 30 having the outer wall 56 and the inner partition wall 60 with the inner partition wall 60 integrally connected to the outer wall 56 to form a distribution chamber 66. The method further includes the step of cutting the tank 30 to a predetermined length. Cutting can be accomplished by any means. The method further includes the step of forming a plurality of apertures 68 in the inner partition wall 60. The plurality of apertures 68 can be produced by any means, including but not limited to, drilling, lancing or punching.

The present invention also provides a method of manufacturing a manifold having a tank 30 with an outer wall 56 defining a channel 58 and an inner partition wall 60 with a plurality of apertures 68, a header 36 having a plurality of openings 54, and at least one end cap 40. The method includes the step of extruding the tank 30 having the outer wall 56 and the inner partition wall 60 with the inner partition wall 60 integrally connected to the outer wall 56 to form a distribution chamber 66. The method further includes the step of cutting the tank 30 to a predetermined length. The tank 30 can be cut using any means. The method further includes the step of forming a plurality of apertures 68 in the inner partition wall 60. The plurality of apertures 68 can be produced by any means, including but not limited to, drilling, lancing or punching. The method further includes the step of forming a plurality of openings 54 in the header 36. This step may be accomplished by a variety of means, including but not limited to forming the plurality of openings 54 when the header 36 is formed. The plurality of openings 54 can be produced by any means, including but not limited to, drilling, lancing or punching. The method further includes the step of joining the tank 30 and the header 36. Joining can be accomplished by a process such as welding and brazing, but is not limited to these processes. The method further includes the step of joining the end cap 40 to one end of the tank 30 and the header 36. Joining the end cap 40 can be accomplished by a process such as welding and brazing, but is not limited to these processes.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. The reference numerals are merely for convenience and are not to be read in any way as limiting. 

1. A heat exchanger assembly) comprising: a first manifold having a tank and a header adjacent said tank and defining a hollow cavity; a second manifold defining a hollow cavity and in spaced and substantially parallel relationship with said first manifold; a plurality of flow tubes extending between and fluidly connecting said cavities of said manifolds for passing refrigerant between said manifolds; and said tank having an outer wall defining a channel and an inner partition wall disposed within said channel adjacent said outer wall with said inner partition wall having a section integrally formed with a portion of said outer wall to define a distribution chamber disposed within said channel with said inner partition wall having a plurality of apertures fluidly connecting said distribution chamber with said cavity.
 2. An assembly as set forth in claim 1 wherein said inner partition wall has a generally C-shaped cross-section.
 3. An assembly as set forth in claim 1 wherein said outer wall includes a pair of opposed longitudinal edges each including a flange integral to and extending outward from said longitudinal edge forming a seat.
 4. An assembly as set forth in claim 3 wherein said header includes a pair of longitudinal edges.
 5. An assembly as set forth in claim 4 wherein said longitudinal edges of said header are adjacent said seats.
 6. An assembly as set forth in claim 1 having at least one port in said first manifold and fluidly connected to at least one of said distribution chamber and said cavity.
 7. An assembly as set forth in claim 6 wherein said port is adjacent at least one of said outer wall and an end cap of said first manifold.
 8. An assembly as set forth in claim 7 wherein said at least one port further includes a coupler adjacent at least one of said outer wall and said end cap and fluidly connected to at least one of said distribution chamber and said cavity.
 9. An assembly as set forth in claim 1 wherein said header includes a plurality of openings sized for accepting said plurality of flow tubes.
 10. An assembly as set forth in claim 1 wherein said flow tubes are disposed within said cavity of said first manifold fluidly connecting said second manifold with said cavity of said first manifold.
 11. An assembly as set forth in claim 1 wherein said inner partition wall includes a flattened ledge running a length of said inner partition wall adjacent said cavity with said plurality of apertures disposed within said ledge.
 12. A manifold comprising: a tank having an outer wall defining a channel; a header mounted to said outer wall with said header and said outer wall defining a cavity; and said tank having an inner partition wall disposed within said channel adjacent said outer wall with said inner partition wall having a section integrally formed with a portion of said outer wall to define a distribution chamber disposed within said channel with said inner partition wall having a plurality of apertures fluidly connecting said distribution chamber with said cavity.
 13. An assembly as set forth in claim 12 wherein said inner partition wall has a generally C-shaped cross-section.
 14. An assembly as set forth in claim 13 wherein said outer wall includes a pair of opposed flanges defining a pair of seats for said header.
 15. An assembly as set forth in claim 14 wherein said header includes a pair of longitudinal edges abutting said seats.
 16. An assembly as set forth in claim 15 having at least one port in said tank and fluidly connected to at least one of said distribution chamber and said cavity.
 17. An assembly as set forth in claim 16 wherein said port is adjacent at least one of said outer wall and an end cap of said first manifold.
 18. An assembly as set forth in claim 17 wherein said at least one port further includes a coupler adjacent at least one of said outer wall and said end cap and fluidly connected to at least one of said distribution chamber and said cavity.
 19. An assembly as set forth in claim 12 wherein said header includes a plurality of openings.
 20. An assembly as set forth in claim 12 wherein said inner partition wall includes a flattened ledge along a length of said inner partition wall facing said cavity with said plurality of apertures disposed within said inner ledge.
 21. A method of manufacturing a tank having an outer wall defining a channel, and an inner partition wall with a plurality of apertures, said method comprising the steps of: extruding the tank having the outer wall and the inner partition wall with the inner partition wall integrally connected to the outer wall to form a distribution chamber; cutting the tank to a predetermined length; and forming a plurality of apertures in the inner partition wall.
 22. A method of manufacturing a manifold having a tank with an outer wall defining a channel and an inner partition wall with a plurality of apertures, a header having a plurality of openings, and at least one end cap, said method comprising the steps of: extruding the tank having the outer wall and the inner partition wall with the inner partition wall integrally connected to the outer wall to form a distribution chamber; cutting the tank to a predetermined length; forming a plurality of apertures in the inner partition wall; forming a plurality of openings in the header; joining the tank and the header; and joining the end cap to one end of the tank and the header. 